This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A049511 #34 Mar 01 2021 07:21:51 %S A049511 5,11,13,18,20,26,32,36,42,43,47,53,54,58,60,64,67,79,82,83,89,94,98, %T A049511 100,105,110,115,116,121,125,126,133,135,141,142,152,156,160,164,167, %U A049511 172,173,177,178,182,190,193,194,197,202,210,212,216,218,221,230,233 %N A049511 Numbers k such that prime(k) == 1 (mod 10). %C A049511 Also k for which prime(k) == 1 (mod 5). - _Bruno Berselli_, Mar 04 2016 %C A049511 The asymptotic density of this sequence is 1/4 (by Dirichlet's theorem). - _Amiram Eldar_, Mar 01 2021 %H A049511 Zak Seidov, <a href="/A049511/b049511.txt">Table of n, a(n) for n = 1..1000</a> %F A049511 a(n) = A000720(A030430(n)). - _Ray Chandler_, Nov 07 2006 %t A049511 Select[Range[210], Mod[Prime[ # ], 10] == 1 &] (* _Ray Chandler_, Nov 07 2006 *) %o A049511 (Sage) [n for n in (1..300) if Mod(nth_prime(n), 10) == 1] # _Bruno Berselli_, Mar 04 2016 %o A049511 (PARI) isok(n) = !((prime(n)-1) % 10); \\ _Michel Marcus_, Mar 04 2016 %Y A049511 Cf. A000720, A024912, A030430, A081759. %Y A049511 Cf. A049508, A049509, A049510. %K A049511 nonn %O A049511 1,1 %A A049511 _N. J. A. Sloane_ %E A049511 Extended by _Ray Chandler_, Nov 28 2003 %E A049511 Formula corrected by _Zak Seidov_, Sep 20 2011